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Description/Abstract

A simple model of a homojunction solar cell is improved by taking into account the effect of photon recycling . The efficiency of converting solar radiation into electricity is studied as a function of the key variables. Some of these can be directly controlled, e.g. the semiconductor layer thickness and the surface recombination velocity. Other variables can be controlled indirectly, by doping, thermal treatments, etc: the internal efficiency of the radiative emission, the carrier lifetime and the minority carrier diffusion coefficient. For actual GaAs solar cells, taking photon recycling into consideration leads to an increase in efficiency of the order of 2%. The results we show are useful for the design and fabrication of solar cells based on wide-gap semiconductors.